Fluid fuel controller



Aug. l, 11933.

C. D. STEWART FLUID FUEL CONTROLLER Filed July 28, 1931 2 Sheets-Sheet l INVENTOR. CARLTON D. STEWART @www ATTORNEY.

Aug. l, 1933. D STEWART ,920,44@

FLUID FUEL CONTROLLER Filed July 28, 1931 2 Sheets-Sheet 2 i INVENTOR. CA RLTON D. ST EWA RT ATTORNEY.

Patented Aug. 1, 1933 PATENT OFF'ICE l 1,920,440 FLUID FUEL coN'raoLLEa Carlton D. Stewart, Berkeley, Calif., assigner to Associated Engineering and Supply Company,

San Francisco, Calif.,

ornia :1Cor-poration of Cali- Application July 26, 1931. Serial No. 553,500

'7 Claims.

This invention relates to apparatus adapted to be employed more particularly in connection with a furnace, for controlling the supply of uid fuel, such as gas or liquid, to the burners of the furnace and for controlling the furnace draft.

One object of my invention is to provide a controlling device of the above character in which leakage oi the operating iuid, which may be either agas under pressure or a liquid, is prevented.

Another object ci my invention is to provide a controlling device having a relay valveY mechanism for controlling the supply and release ci the operating fluid to and from the controlling piston and a pilot valve mechanism vfor controlling the operation 0I" the relay valve mechanism.

Other objects and advantages will appear in the following more detailed description of the invention.

in the accompanying drawings; Fig. 1 is a front elevation of a typical furnace, showing my improved controlling apparatus associated therewith; Fig. 2 is a side elevation of the furnace shown in Fig. i; Fig. 3 is a diagrammatic sectional view of the improved controlling device; Fig. 4 a side elevation, partially sectioned on the line 4-4 of Fig. 3 of the device shown in Fig. 3; and ll'ig. 5 an enlarged sectional view of one of the pilot valve devices. i

.As shown in Figs. l and 2, my improved controlling device 1 is supported by a bracket 2 which is secured to a furnace 3. Projecting downwardly troni the device 1 are piston rods 4 and 5 to the ends of which are connected the ends of a chain 5. The chain 6 runs over a pulley 7 which is carried at one endof a rod 8. The other end of the rod is pivotally connected to an arm 9, secured to a shaft 10.

The shaft l@ is supported on the furnace in bearings provided in brackets 11, secured to the furnace 3. A valve device l2 adapted to vary the rate of Yflow oi iiuid fuel to the burners of the furnace is interposed in a fuel supply pipe 13 and said valve device is provided with an operat- 45 ing arm 14. The arm 14 is operatively connected to an arm 9@ secured to the shaft 10, through a rod i5.

Carried rby the shaft 10 is an arm 16 to whichis connected a chain 1'? for operating a lever 13, which controls a stack damper 19. Arms`26 secured to the shaft 19 are connected by chains 21 to ash pit door dempers 22.

The controlling device comprises a housing 23 having at its upper open end a diaphragm 24,

which is clampedpto the housing byv a cover plate -in the screw.

25. Secured to the under face of the diaphragm is a follower plate 26. A stud 27 having a conical socket 28 is screwed into the plate 26 and they upper rounded end of a diaphragm rod 29 engages in said socket.Y Mounted on the rod 29 is a mov- 60 ablefollower plate 30 and interposed between the plates 26 and 30 is a coil spring 31.

A pressure regulating screw 32 has screwthreaded engagement in the end wall 33 of the housing 23, the rod 29 extending through a bore 65 The end of the screw 32 engages the follower plate 30, so that by adjusting the screw, the pressure with which the spring 31 presses against the diaphragm 24 may be regultd.

A steam supply pipe 34 is connected to the chamber 35 above the diaphragm 24, and said pipe is connected to a steam header 36, so 'that the diaphragm 24 is subjected to the opposing pressures of the steam generated by the boilers of the iurnace 3 and the spring 31.

Extending downwardly from the housing 23 are standards 37, which are spaced apart, and secured to the lower ends of the standards by bolts 38A is a pilot valve housing 39. Secured to the under face of the housing 39 is a cylinder casting 40, having piston cylinders 41 and 42 containing pistons 43 and 44 connected to the respective piston rods 4 and 5.

in the housing 39 are mounted two pilot valve mechanisms, each comprising an exhaust valve 45 having a stem 46. A bonnet 47 is provided for each exhaust valve, and each bonnet is provided with a threaded extension 47a which is screwed into the housing 39, so as to permit a shoulder 48 thereof to engage a gasket 49, mounted in the bonnet. Each bonnet is also provided with a flange 50 adapted to engage a corresponding face of the housing 39.

Mounted in a threaded upward extension 51 of each bonnet is a bushing 52 in which each valve stem 46 is adapted to slide. Each bonnet is provided with an axial bore 53, at the upper end of which is a conical seat 54, against which a spherical inlet valve 55 is adapted to engage. Each valve 55 is provided with an upwardly extending stem 56 `having a conical seat 5'? at its upper end against which `the exhaust valve 45 is adapted to seat.

Extending through the stem 56 from the seat 57 is an axial passage 58, having radial passages 59 at its lower end which open into a chamber 60, and passage 61 connects chamber 60 with a chamber 62.

Valve chamber 63 of the exhaust valve 45 is 110 connected to passages 64 in the bonnet 47, which passages extend to an annular groove 65 at theV face of the flange 50, adapted to register with a passage 66.

Each exhaust valve stem 46 is provided with a head 67 at its upper end, and interposed between said head and the nut 68 is a coil spring 69 which surrounds the stem 46. A coil spring 70 interposed between a portion of the housing 39 and the inlet valve 55, which urges the valve to its seat.

For operating the valve stems 46, an equalizer bar 72 is provided. Said bar is provided with'A bearings '73 having bores to receive a shaft 74. The shaft 74 is mounted Ain bearings '75 carried by the standards 37. A cap screw 76 extends through a bore in the bar 72and is provided with a rounded end adapted to engage in a corresponding recess provided at the lower end of the diaphragm 'rod 29, the cap screw being secured to the bar 72 by a nut '77.

Threaded into the bar 72-in axial alinement with each valve stem 46 is an adjustable cap screw 78, the head ofthe-cap screwV being adapted to engage the head 67 of each valve stem 46.

Each pilot `valve device controls the operation of a relay valve'device, each comprising a dif- VV`ferential piston having piston heads 80 and 8l.

A iiexible 'diaphragm 82 engages the upper vface of each kpiston head V8f3-and is subject to the Ypressure of `fluid supplied from chamber 62 of each Apilot lvalve device, through passage 83.

Each differential piston is provided with a downwardly extending stem 84 adapted to engage a 'ball exhaust valve 85, contained in valve chamber 86 and spaced axially from the exhaust valve is a ball inlet valve 87, lcontained in valve chamber 88. j

interposed between the ball valves 85 and 87 is a valve spacer 89, so that when the `ball valve 85` is moved to its seatbythe stem 84, the valve 'lis unseatedby the movement of the spacer 89. Y A coil spring 90 urges each Vvalve 87 to its seat and through the spacer 89 urges the valve 85 away from its seat.

A iiuidsupply pipe-`9l supplies iiuid, preferably aliquid under pressure, such as water, through passage 92 and passage `93 to the chamber 53 of each pilot valve device, and an exhaust or drain pipe 94 is connected to passage 95 which'lea'ds to the valve chambers 86. Each valve chamber 86 is connected to a passage 96 which opens into the respective cylinders 41 and 42 near their upper ends, and the space intermediate the valves`85 and 87 is connected to apassage 97 which lopens to the respective cylvinders-41-and 42 near their lower ends.

The apparatus shown is adapted to regulate the rate of iiow of fluid fuel and the positioning of the dampers for a maximum hre, a medium fire, and a minimum nre.

In Figs. 3 and 4, the parts are shown positioned for a medium fire. The steam pressuresupplied from the steam boilers, acting in chamber 35, is such as to depress the diaphragm 24 moderately, so that the equalizer bar Vis moved to a position, by the diaphragm rod 29, in which the right hand exhaust valve 45 seats on its seat in the valve stern 56 and the inlet valve 55 is unseated. Fluid under pressure `is thenlsupplied from. the fluid pressure supply pipe 91,` through passage 92, passage 93, and

y chamber 53, past the open valve 55 to chamber 60, and thence through passage 61 and chamber 62`to passage 83, which leads to the chamber above the diaphragm 82. The diaphragm 82 at upwardly VThe spring 70, acting on the right is thus depressed, causing the piston heads 80 and 81 to be moved downwardly, so that the stem 84 acts to seat the valve 85, and through the spacer 39, to unseat the bail valve 87.

The ball valve 87, being unseated, iluid under pressure is supplied from the supply pipe 91, through chamber 88, past the unseated valve 87 to passage 97, and thence to the cylinder 42. below thepiston 44. The piston 44 is thus moved to its upper position, as shown, the chamber above the piston 44 being open at all times to the exhaust pipe 94 by way of passage 96 and passage 95.

In the medium fire position, the valve 45 at the left of the drawings, Fig. 3, remains unseated, so that the valve 55 is held seated by the spring 70. The valve 45 at the left being unseated, the chamber abovethe left hand diaphragm 82 is open to the exhaust pipe 94 by way of passage 83, chamber 62, passage 61, radial ports 59 and port 58 in the valve stem 56, and past the unseated valve 45 to valve chamber 63. From valve chamber 63, fluid is exhausted through passage 64, passage 66 to the chamber above the piston 43, which chamber is connected to the exhaust pipe 94, 'by way of passages 96 and 95.

The diaphragm at the left not being subject to fluid under pressure, the spring 90 is permitted to seat the inlet valve 67 and through the spacer 89 to unseat the exhaust valve 85. The cylinder space below the piston 43 is then vented to the exhaust pipe 94 through passage 97, past the unseated valve 85 and through passage 95, which leads to the pipe If the steam pressure acting in diaphragm chamber 35 should increase above that which maintains the diaphragm 24 in the position shown in Fig. 4, the diaphragm 24 will bev further depressed against the pressure of spring 31, so that the equalizer bar 72 is operated to shift the stem 46 of the left hand pilot valve device downwardly, causing the exhaust valve 45 to rst seat, and then causing movement of the valve stem 56 so as to unseat the inlet valve 55.

Fluid under pressure is then supplied through passage 88 to the left hand diaphragm 82, causing the piston heads 80 and 8l to be shifted downwardly in the same manner described in iio connection with the relay valve device at the.`

right. The exhaust valve 85 is thus seated and the inlet valve 87 unseated, so that fluid under pressure is .supplied through passage 97 to the piston cylinder 4l below the piston 42. The pis` ton 43 is then shifted upwardly, so that the piston rod 4 is operated to pull up on the chain 6 and thus cause an upward Vmovement of the rod 8.

The arm 9 is then operated to cause rotation of the shaft 10, so that the dempers 19 and 22 are shifted to restrict the draft, while the arm 9e operates through the rod l5 to turn the arm 14, so as to operate the fuel supply valve device 12 to close oli or greatly restrict the flow oi fluid fuel to the burners of the furnace.

If the steam pressure should become reduced from that which acts to hold the diaphragm 24 in the position shown in Fig. 4, the diaphragm 24 will be moved upwardly from that position, by the spring 31. This relieves the pressure transmitted through the diaphragm rod 29 to the equalizer bar 72, `so that the spring 69 is permitted to shift the valve steml'46 at the right the inlet valve 55, then 'operates to move the valve 55 to its seat. When the valve 55 is seated, the spring 69 further' acts to move the stem 46 so that the exhaust valve 45 is unseated.

With the inlet valve 55 seated and the exhaust valve 45 unseated, as above described, fluid is vented from the diaphragm 82 at the right, so that the valve 87 is permitted to seat by the action of the spring 90, while the valve 85 is unseated. With the valve 85 unseated, fluid is vented from the cylinder 42, below piston 44, so that the piston 44 moves downwardly by gravity. The piston rod 5 is thus moved downwardly, so that the chain 6 is let down and the arm 9 is permitted to assume a lower position, than that shown in Fig. 2, in which movement the shaft 10 is rotated to cause the .fuel supply valve 12 to be operated so as to increase the rate of flow of fluid fuel to the burners, while the arms 16 and 20 are operated to cause the dampers 19 and 22 to be opened to permit an increased draft.

By employing the above described pilot and relay valve construction, there is no continual waste or drainage of operating fluid, since fluid is only vented to the exhaust pipe when the parts are actually moving from one position to another.

The features of equalizing bar construction are not claimed in this application, since they are the invention of James W. Harrie, as disclosed in an application, Serial No. 566,664, led October 3, 1931.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims.

Having now described my claim as new and desire to secure by Patent, is:

1. In a fluid fuel burning apparatus, the combination with a fuel supply valve device, of a piston operatively connected to said valve device, and operated by supplying and releasing fluid under pressure to and from said piston through a passage terminating in oppositely facing valve seats, a ball valve adapted to engage one valve seat for controlling the supply of fluid under pressure to the chamber at one side of said piston, a ball valve adapted to engage the other Yvalve seat for controlling the release of fluid from said chamber, a movable member interposed between and engaging said ball valves, a movable abutment` operated by variations in fluid pressure for actuating said valves, and means for varying the fluid pressure on lsaid abutment.

2. In a fluid fuel burning apparatus, the combination with a fuel supply valve device, of a piston operatively connected to said valve device, and operated by supplying and releasing nuid under pressure to and from said piston through a passage terminating in oppositely facing valve seats, a ball valve adapted to engage one valve seat for controlling the supply of fluid under pressure to the chamber at one side of said piston, a ball valve adapted to engage the other valve seat for controlling the release of fluid from said chamber, a member interposed between said valves for actuating one valve upon movement of the other valve, a movable abutment operated by variations in fluid pressure for invention, what I Letters operating said valves, and means for varying the fluid pressure on said abutment.

3. In a fluid fuel burning apparatus, the combination with means for controlling the supply of fuel including a piston operated by variations in fluid pressure, a relay valve means operated by variations in iluid pressure for varying the pressure on said piston, and a pilot valve device forl controlling the operation of said relay valve means comprising an inlet valve for controlling the supply of fluid under pressure to said relay valve means, and having a valve stem, and an exhaust valve for controlling the exhaust of fluid from said relay valve means, said exhaust valve being movable to operate said stem to open said inlet valve.

4.` In a fluid fuel burning apparatus, the combination with means for controlling the supply of fuel including a piston operated by variations in fluid pressure, a relay valve means operated by variations in fluid pressure for varying the pressure on said piston, and a pilot valve device for controlling the operation of said relay valve means comprising an inlet valve for controlling the supply of fluid under pressure to said relay valve means, and having a valve stem provided with a passage through which fluid is exhausted from said Yrelay valve means, an exhaust valve controlling communication through said passage and movable to operate vsaid stem and thereby said inlet valve.

5. In a fluid fuel' burning apparatus, the combination with means for controlling the supply of fluid fuel including a piston operable by variations in fluid pressure, of a relay valve means 1 for controlling the supplyand release of fluid under pressure to and from said piston and operable to cut off the exhaust of fluid from said piston upon operation to supply fluid under pressure thereto, and pilot valve means for controlling the operation of said relay valve means.

6. In av fluid fuel burning apparatus, the combination with means for controlling the supply of fluid fuel including a piston operable by variations in fluid pressure, of a relay valve means for controlling the supply and release of fluid under pressure to and from said piston and comprising an inlet valve for controlling the supply of fluid under pressure to said piston, an exhaust valve for controlling the exhaust of fluid from said piston, and means operable to close the ex-` haust valve upon opening the inlet valve, and a pilot valve means for controlling the operation of said relay valve means.

'7. In a fluid fuel burning apparatus, the combination with means for controlling the supply of fluid fuel including a movable abutment operable by variations in fluid under pressure, of a fluid under pressure supply pipe, a relay valve means operated by fluid under pressure for supplying fluid under pressure from said supply pipe to said piston and for simultaneously cutting off the exhaust of fluid from said piston, a pilot valve means operable to supply iluid under pressure from said supply pipe to said relay valve means and simultaneously cut off the release of uid from said relay valve means, and means for controlling the operation of said pilot valve means.

CARLTON D. STEWART. 

